package com.fuxi;

public class SheetPolymorphism {

}
abstract class Shape{
	abstract public double area();
}
class Rectangle extends Shape{
	double width;
	double height;
	
	public  double area() {
		return this.width * this.height;
	}
}
class Circle1 extends Shape{
	double radius;
	@Override
	public  double area() {
		return 3.14 * radius * radius;
	}	
}
class Cylinder1 extends Circle1{


	
}